PATIENT CHARACTERISTICS: Age: 18 and over Performance status: See Disease Characteristics Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: See Disease Characteristics WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin normal SGOT/SGPT no greater than 1.5 times upper limit of normal (ULN) Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No significant cardiovascular disease No New York Heart Association class III or IV heart disease No active angina pectoris No myocardial infarction within the last 6 months Ejection fraction at least 45% by echocardiogram or MUGA No prior hemorrhagic or thrombotic cerebral vascular accident No deep venous thrombosis Pulmonary: No pulmonary embolism within the past 6 months Other: No history of bleeding disorder or gastrointestinal bleeding that would preclude anticoagulation with warfarin No other concurrent malignancy except non-melanoma skin cancer or any curatively treated malignancy considered to be at less than 30% risk of relapse No severe infection No severe malnutrition No other serious medical illness that would preclude study